SEL-451
Protection, Automation, and Bay Control System
Advanced feeder protection and
complete substation bay control in one
economical system
• Customize distribution protection using multiple instantaneous,
time-overcurrent, and directional elements.
• Detect high-impedance faults with Arc Sense™ technology (AST).
• Implement bay control with complete two-breaker control and
high-speed breaker failure detection.
• Transform the way you modernize your substation with SEL
Time-Domain Link (TiDL®) and Sampled Values (SV) technologies.
Functional Overview
Bus
ANSI Numbers/Acronyms and Functions
25
27
32 (O,U)
50
50BF
51
52PB
59
67
79
81 (O,U)
1
3
SEL-451
Line
25
27
32OU
50
50BF
51
52PB
59
67
79
81OU
85
RIO
BRM
DFR
HIZ
HBL
HMI
LGC
LOC
MET
PMU
SER
SBM
SIP
Additional Functions
3
THM
1
4
2
IRIG-B
EIA-232
Ethernet1*
SEL-451-5
3
Bus
16 SEC
50G
85 RIO
BRM
DFR
HBL
HIZ
HMI
LDE
LGC
LOC
MET
PMU
SBM
SER
SIP
SV
THM
TiDL
16 SEC
1
2
Synchronism Check
Undervoltage
Over- and Underpower
RMS Overcurrent
Dual Breaker Failure Overcurrent
Time-Overcurrent
Trip/Close Pushbuttons*
Overvoltage
Directional Overcurrent
Autoreclosing
Over-/Underfrequency
2
Ethernet
Ethernet
Station Bus Process Bus
SEL-451-6†
Access Security (Serial, Ethernet)
Best Choice Ground
SEL Mirrored Bits® Communications
Breaker Wear Monitor
Event Reports
Harmonic Blocking
High-Impedance Fault Detection AST*
Operator Interface
Load Encroachment
Expanded SELogic® Control Equations
Fault Locator
High-Accuracy Metering
Synchrophasors
Station Battery Monitor
Sequential Events Recorder
Software-Invertible Polarities
IEC 61850-9-2 Sampled Values Technology*†
IEC 60255-Compliant Thermal Model
Time-Domain Link Technology*
Copper or fiber-optic *Optional feature
1
SV subscriber relays have no analog input boards and instead receive
voltages and current through Ethernet.
†
Key Features
Comprehensive Feeder Protection
Customize distribution protection in the SEL-451
Protection, Automation, and Bay Control System with
multiple instantaneous, time-overcurrent, and directional
elements combined with SELogic control equations. AST
detects high-impedance faults, while low-energy analog
(LEA) voltage inputs help protect pad-mounted switchgear.
Powerful Bay Control and High-Speed Breaker Protection
Comprehensive two-breaker control and breaker failure
protection complement the versatility of the SEL-451
programmable logic to meet your bay control needs. Easily
control motor-operated switches, capacitor banks, and
field I/O from the front panel or remotely.
Built-In Real-Time Synchrophasor Measurements
Help system operators understand the network status
with real-time visual displays of system phase angles
and frequency. High-accuracy synchronized phasor
measurements provide information and control to match
the frequency and phase angle for critical activities, such
as switching, startup, and power transfer.
Monitoring That Maximizes the Capability of Substation
Equipment
Fully load equipment by monitoring power, including
thermal or rolling interval demand as well as peak demand
on positive-, negative-, and zero-sequence current.
Digital Secondary System Technologies
Modernize your substation by applying SEL TiDL
technology or SEL SV technology. Both of these digital
secondary system solutions replace copper wires with
fiber-optic cables to increase safety, reduce costs
associated with using copper wires, and limit the impact
of electromagnetic interference.
TiDL is a simple and secure digital secondary system
solution that is easy to implement, with no external time
source or network engineering required. Apply the TiDLenabled SEL-451-5 in the control house with the SEL-2240
Axion® TiDL node in the yard, which provides remote I/O,
digitizes analog signals, and sends the signals over fiberoptic cables to the relay.
SEL SV combines protection in the merging unit with
the flexibility of IEC 61850-9-2 to increase power system
reliability. Apply the SEL-451-6 with SEL SV technology to
receive IEC 61850-9-2 SV data over fiber-optic cables from
SEL merging units or other SV-compliant units.
Product Overview—SEL-451-5 Relay
EIA-232 front serial port is quick
and convenient for system setup
and local access.
Easy-to-use keypad aids
simple navigation.
Interactive bay display with userconfigurable apparatus labels
allows the operator to view the
status of breakers and disconnect
switches and to control them.
Front-panel LEDs indicate custom
alarms and provide fast and simple
information to assist dispatchers and
line crews with rapid power restoration.
Programmable operator pushbuttons
with user-configurable labels allow
front-panel customization.
Choose from a vertical or horizontal,
panel-mount or rack-mount chassis
and different size options.
Use a maximum of
68 output contacts.1
Communications protocols include FTP,
Telnet, synchrophasors, DNP3 LAN/WAN,
the Parallel Redundancy Protocol (PRP), the
IEEE 1588 Precision Time Protocol Version 2
(PTPv2),** and IEC 61850 Edition 2.
Order six current inputs in standard
terminal blocks (as shown) or a
Connectorized® hardware configuration.
Choose six voltage inputs in either standard
terminal blocks, a Connectorized hardware
configuration, or an LEA hardware configuration.
Use one front and three rear
EIA-232 ports for Mirrored Bits
communications, DNP3, SCADA,
and engineering access.
Use a maximum of
103 input contacts.1
Choose from power supply
options such as 24–48 Vdc;
48–125 Vdc or 110–120 Vac; or
125–250 Vdc or 110–240 Vac.
Requires 8U chassis
1
**For PTP implementation, Ports 5A and 5B
must be ordered as an option.
Applications
Protection
Complete Overcurrent Protection
Pad-Mounted Switchgear Protection
Customize distribution protection with multiple
instantaneous and time-overcurrent elements
combined with SELogic control equations. You can
select from four phase, four negative-sequence, and
four ground instantaneous overcurrent elements
to best fit your application. Best Choice Ground
Directional Element® logic optimizes directional
element performance and eliminates the need
for many directional settings.
Protect pad-mounted switchgear using the SEL-451 with
LEA voltage inputs. This helps reduce overall system
costs by eliminating amplification electronics between
the line sensor and the relay. Having fewer devices leads
to a simpler system, a reduction in labor costs, and the
elimination of a possible point of failure.
Electric
Voltage Divider
High-Impedance Fault Detection
Detect high-impedance faults with AST. Highimpedance faults are a common result of a downed
conductor on surfaces with poor conductivity. With
AST, alarm or trip for faults that produce low fault
current and are undetectable with conventional
overcurrent relays.
C1
Cable
SEL-451
Vpri
C2
Cc
Vsec
VY or VZ Terminal
Voltage Input
(8 Vac LEA input)
Bay Control
BAYNAME
Two-Breaker Bay Control
Meet your bay control needs with complete two-breaker
control and high-speed breaker failure detection. You can
easily control motor-operated switches, capacitor banks,
and field I/O from the front panel or remotely. Configurable
labels make it easy to customize the relay controls to
match your application. Different bus configurations are
available, including single- and dual-busbar, transfer bus,
tie-breaker, breaker-and-a-half, ring-bus (shown in the
figure), double-bus/double-breaker, and source-transfer
configurations.
BAYLAB1
SW1
BAYLAB2
BK1
BK2
SW2
Flexible I/O Options
SW3
Select different combinations of I/O boards to match each
application. The SEL-451 supports up to four additional I/O
boards for a total of up to 103 inputs and up to 68 outputs
depending on configuration.
NAVIG
6 ANALOGS
I:99999.9 A
V:9999.9 KV
P:9999.9 MW
Q:9999.9 MV
F:99.9 HZ
ESC
Panel Integration
Racked Breaker Support
Support racked breakers where they are used. Racked
breaker mosaics provide visual indication of not only
whether the breaker is open or closed but also for which
position the breaker is in (racked in, test, or racked out).
Disconnect Monitoring and Control
Use up to 20 disconnects for bay control applications. All
disconnects can be either controlled or in a monitor-only
state. A setting for each disconnect allows you to tailor it
for each application.
Improve efficiency and simplify installation with more
target LEDs and operator pushbuttons. The 4U, 5U, and
8U chassis have options for an additional eight target
LEDs and four operator control pushbuttons. You can
also include arc-suppressed trip/close pushbuttons for
an enhanced solution.
Display the breaker status and control the breaker
position, even if the relay is not powered, with auxiliary
breaker trip/close control pushbuttons and indicating
lamps. The 24 target LEDs indicate the relay state and
various trip conditions and are configurable for specific
applications. You can modify the 12 operator pushbuttons
to replace traditional panel switches and meet operator
control needs.
+
+
Close
(manual/local)
Remote Close/
Autoreclose
Breakerr
Open
n
Breaker
Breaker
B
C
losed
Closed
43
local
43
4
local
52a
To Close Circuit
52b
-
52
TC
-
Trip
(manual/local)
Remote Trip/
Protection Trips
Automation
VAR-Supervised Time-Undervoltage Characteristic
Custom Automation With SELogic Control Equations
Create your own custom applications using powerful SELogic
control equations. This allows you to:
15
• Prevent cascading voltage collapse using VAR-supervised
time-undervoltage elements.
• Create an adaptive inverse-time overcurrent characteristic
to adjust pickup based on load conditions.
• Protect ungrounded-wye shunt capacitor banks.
10
Time (s)
• Monitor VAR loading, and trip only the feeders with high
VAR demand to prevent voltage collapse.
5
Trip Time
• Create your own custom curves.
0
0.5
1.0
Voltage Per Unit
Harmonic Analysis
120
Harmonic Monitoring
110
Harmonics % of Fundamental
Apply the second-, fourth-, and fifth-harmonic elements
with individual threshold settings to detect transformer
energization and overexcitation conditions. You can use
the output from these harmonic detection elements for
a variety of functions. For example, modifying the relay
settings can improve security, and event reporting makes
the identification of transformer energization events fast
and simple.
100
90
80
70
60
50
40
30
20
10
60
120
180
240
300
360
420
Frequency
Breaker Wear Monitoring
Excess Breaker
Contact Wear
Compare the breaker manufacturer’s published data to
the actual interrupted current and number of operations
for two breakers, and create alarms accordingly. By
monitoring the mechanical and electrical interruption
time per pole, you can compare average and last trip
times for maintenance scheduling.
Excess Mechanical
Operating Time
Excess Electrical
Operating Time
Excess Pole Scatter or
Pole Discrepancy
Phase Currents
Auxiliary Contact
Inputs
Station Battery
Voltages
Relay
Circuit
Breaker
Monitor
Excess Breaker
Inactivity Time
Excess Motor Running
Time
Excess kA
Interrupted
Deviations in Station
Battery Voltages
Enhanced Event Analysis Software
Synchrophasors
Use the SEL-451 as a multichannel (six voltages,
six currents) digital fault recorder. With SEL-5601-2
®
synchroWAVe Event Software, you can view COMTRADE
files from the SEL-451 and other digital fault recorders.
Event resolutions from 1 to 8 kHz and event report
lengths from 0.25 to 24.00 seconds (1 kHz resolution)
are possible. You can perform harmonic analysis of any
voltage or current and select the prefault, fault, or postfault portion of the event report to examine.
Significantly improve your system’s performance with
SEL’s complete synchrophasor solutions, including
hardware, communications, viewing and analysis
software, data collection, and data archiving. The
SEL-451 provides real-time system state measurement
with time-synchronized voltages and currents in the
IEEE C37.118 standard format. In addition, SEL-5078-2
synchroWAVe Central Software or third-party software
allow you to view and analyze system phase angles,
load oscillations, voltage profiles, and other critical
system information.
TiDL Technology
In a TiDL solution, Axion TiDL nodes are placed in the
yard close to the primary equipment to digitize discrete
I/O signals and analog data and then transport them over
a fiber-optic cable to the TiDL-enabled SEL-451 in the
control house.
This innovative technology uses point-to-point connections
and a nonroutable protocol, providing a simple and secure
solution. Because it does not require an external time
source or Ethernet switches, it is easy to implement with
no network engineering required.
TiDL combines the proven protection of the SEL-400
series relays with the modularity of the Axion, reducing
training requirements and providing a scalable and flexible
solution. It also provides built-in time synchronization and
synchronous sampling, ensuring protection is available in
the relay regardless of whether or not an external time
signal is available.
Substation Yard
IAW, IBW, ICW
VAY,
VBY,
VCY
VAY,
VBY,
VCY
SEL-2240
Axion
SEL-2240
Axion
IAW, IBW, ICW
SEL-2240
Axion
Feeder 1
SEL-2240
Axion
Feeder 2
VAZ
(sync.
check)
Fiber-Optic Cable
SEL-2240
Axion
SEL-451
Control House
SEL-451
SEL-451-5 With TiDL Technology
4U chassis with mounting options (vertical
or horizontal; panel or rack) accommodates
your application needs.
Commission button usage prompts
the relay to communicate with the
Axion TiDL nodes.
LEDs indicate the connection
status to a remote Axion TiDL
node on a per-port basis.
Eight 100 Mbps fiber-optic ports allow the TiDL-enabled relay to
connect with eight remote Axion TiDL nodes and to receive remote
analog and digital data.
LEDs indicate a valid configuration
and successful commissioning.
SEL SV Technology
In an SEL SV solution, the SEL-451-6 Relay (subscriber) in
the control house receives digitized analog signals from
an SV merging unit (publisher) in the yard via a fiberbased Ethernet network. The system uses precise time
synchronization via IRIG-B or PTP.
The SEL-451-6 offers the traditional protection available
in the SEL-451-5 and can also receive SV data. Because all
SEL SV devices are compliant with IEC 61850-9-2 and the
UCA 61850-9-2LE guideline, they can be used with primary
equipment that generates similar SV streams, with other
manufacturers’ SV-compliant units, or with SEL merging
units that offer built-in protection (such as the SEL-401
Merging Unit and the SEL-421-7 Protection, Automation,
and Control Merging Unit).
SEL SV technology allows you to create a flexible
Ethernet-based point-to-multipoint network using tools
such as software-defined networks or VLANs to fit your
application needs. You can use the SEL-2740S SoftwareDefined Network Switch to provide centralized traffic
engineering and improve Ethernet performance. The
switch acts as a transparent PTP clock that supports the
IEEE C37.238 power system profile, ensuring submicrosecond time synchronization of the end devices.
Substation Yard
VAY,
VBY,
VCY
IAW,
IBW,
ICW
IAW,
IBW,
ICW
SEL-401
SEL-401
Feeder 1
Control House
Feeder 2
Fiber-Optic Cable
GPS Clock
Ethernet Switch SEL-2740S
SEL-451
SEL-2488
SEL-451
SEL-451-6 With SV Technology
The 4U chassis has
various mounting options to
accommodate hardware needs.
Select fiber-optic, copper,
or mixed Ethernet with
separate ports for SV data
and engineering access.
Choose from power supply options
such as 24–48 Vdc; 48–125 Vdc
or 110–120 Vac; or 125–250 Vdc or
110–240 Vac.
Accessibility and Communications
Built-In Web Server
Access basic SEL-451 information on a
standard Ethernet network with the built-in
web server. From there you can view the
relay status, Sequential Events Recorder
(SER) data, metering information, and
settings with easy access within a local
network. For increased security, web server
access requires a relay password and the
information is limited to a read-only view.
Mirrored Bits Communications
This field-proven technology provides
simple and powerful bidirectional
digital communications between
devices. Mirrored Bits communications
can transmit/receive information
between upstream relays and downstream recloser controls to enhance
coordination and generate faster
tripping for downstream faults.
Ethernet-Based Communications
An Ethernet card option provides
two copper, fiber, or mixed ports for
failover redundancy. Simplify the
Ethernet network topology and reduce
external equipment with dual Ethernet
ports that offer a switched mode for
looped Ethernet networks. Available
Ethernet communications protocols
include FTP, Telnet, DNP3 LAN/WAN,
IEEE 1588 PTPv2, IEC 61850 Edition 2,
IEEE C37.118 synchrophasors, and PRP.
52
52
SEL-421
SEL-451
SEL-421
MIRRORED BITS Communications
Digital, Analog, or Virtual Terminal
®
Engineering
Access
SEL-451
Wide-Area
Network
SEL-2488
GPS Clock
Ethernet
Switch
SEL-451
SEL-2740S
SEL-487B
SEL-421
SEL-3530
SEL-451
SEL-451 Specifications
General
AC Current Inputs
(6 total)
5 A nominal
AC Voltage Inputs
(6 total)
300 VL-N continuous, 600 Vac for 10 seconds
LEA Voltage Inputs
0–8 VL-N continuous, 300 Vac for 10 seconds
Serial
1 front-panel and 3 rear-panel EIA-232 serial ports
1 A nominal
300–57,600 bps
Ethernet
Communications protocols include FTP, Telnet,
synchrophasors, DNP3 LAN/WAN, PRP, PTPv2, and
IEC 61850 Edition 2 (optional).
Choose from the following port options:
Two 100BASE-FX fiber-optic network ports
Two 10/100BASE-T twisted-pair network ports
One 10/100BASE-T twisted-pair network port and one
100BASE-FX fiber-optic network port
TiDL Ports
Fiber-optic ports: 8
Range: ~2 km
Data rate: 100 Mbps
SV Ports
Choose from the following communications port options:
Four 10/100BASE-T twisted-pair network ports
Four 100BASE-FX fiber-optic network ports
Two 10/100BASE-T twisted-pair network ports and two
100BASE-FX fiber-optic network ports
Subscriber: As many as 7 SV data streams
Data rate: 80 samples per cycle
Precise-Time
Input
Demodulated IRIG-B time input and PTPv2
Synchrophasors
IEEE C37.118 standard
Up to 60 messages per second
Processing
AC voltage and current inputs: 8,000 samples per second
Protection and control processing: 8 times per power
system cycle
Power Supply
24–48 Vdc
48–125 Vdc or 110–120 Vac
125–250 Vdc or 110–240 Vac
Operating
Temperature
–40° to +85°C (–40° to +185°F)
Note: LCD contrast is impaired for temperatures below
–20°C (–4°F) and above +70°C (+158°F).
Making Electric Power Safer, More Reliable, and More Economical
+1.509.332.1890 | info@selinc.com | selinc.com
© 2019 by Schweitzer Engineering Laboratories, Inc.
PF00074 · 20190729